A barcode scanner may scan a barcode repeatedly as a barcoded item is dragged across an in-counter scanner. This creates a dilemma: does a duplicate barcode scan belong to an item scanned twice, or is it from a new item? The tolerance for these errors (i.e., singulation errors) is low, as they are frustrating in a retail-checkout setting.
In-counter scanners typically have a large field of view and multiple scan lines to capture barcodes in a variety of positions. Small barcode labels (e.g., Data-Bar barcodes found on fruits and vegetables), however, may not intersect well with the multiple scan lines. This fact may contribute to singulation errors.
To eliminate singulation errors, a scanner may ignore duplicate scans from the same barcode for some period (i.e., timeout period) after a barcode is first scanned. Timeout-periods work well in most scenarios but may not be sufficient for items requiring a weight measurement (especially when small barcodes are used).
Weight measurements may be made using a scale integrated with a scanner (i.e., scanner/scale) so that weighed items remain in the scanner's field of view during a measurement. This weight measurement, however, may require a weighed item to remain in the scan area longer than the timeout period. What is more, items with small barcodes may be easily positioned so that their barcode is not visible to the scanner. As a result, the timeout period may be allowed to expire as the item is weighed, and the barcode may be re-scanned as the item is removed from the scale. A need, therefore, exists for a method and system to improve a barcode-scanner's ability to minimize multiple scan errors for items weighed during checkout.